An electrostatic generator has been proposed as a means for converting mechanical energy into electric field energy, while an electrostatic motor is known as a means for converting electric field energy into mechanical energy.
Such electrostatic motor has a long history and investigations have already been started from 19th century. For example, it is described in detail in the "HANDBOOK OF STATIC ELECTRICITY", P664 P675, written by Academic Circles of Static Electricity, published by OHM PUBLICATION CO.
This paper refers to an induction motor utilizing delayed polarization of dielectric material.
This induction motor is based on the principle that a dielectric material placed under the electric field is poralized and such delayed poralization is used.
Namely, as shown in FIG. 8, in case an inductor b as a rotor is placed within the rotary field within a stator a, an induced load of dielectric material b is deviated in angle from the rotary field due to time delay. A mutual effect between charge and rotary field becomes a rotating force.
Moreover, a motor using a resistance material in place of dielectric material is also proposed. This motor utilizes charges induced within the resistance material under the rotary field are delayed to control direction of field.
However, a conventional electrostatic motor has following problems.
(1) An induction motor described above cannot utilize films because an absorbing force is generated between a resistance material and electrodes.
(2) This motor is formed by a rotary mechanism providing a certain gap between stator and rotor. A mechanism such as bearing is used to hold such gap. Therefore, it is difficult to form narrow gap for a wider area. Moreover, realization of narrow gap will require sufficiently thick stator and rotor to obtain high rigidity and thereby a force density (force generated in the unit area) may be deteriorated.
Accordingly, it is difficult to form a compact induction motor and it has only a low force density.